The present invention is directed to a method for data reduction of digital image sequences in hierarchic fashion by means of a multi-stage coder, using vector quantization and movement compensation as well as reconstruction of these image sequences by means of a multi-stage decoder.
Various methods for adaptive interframe vector quantizing having vector dimensions from 3 through 24 are known, cf. Conference Publication No. 265, pages 200-204, KDD Research and Development Laboratories, Japan, H. Yamaguchi, M. Wada, H. Yamamoto, "64 KB/S INTEGRATED VISUAL TELECOMMUNICATION SYSTEM" or, respectively, ICASSP 86, Tokyo, ANNEX F, pages 133 through 136, Mitsubishi Electric Corporation, Tokumichi Murakami, Kohtaro Asai, Atsushi Itoh, "VECTOR QUANTIZATION OF COLOR IMAGES", wherein the luminance components and color components are quantized in closed fashion. In order to increase the data reduction, the image-to-image differences are reduced by movement compensation (block matching methods) and background prediction (KDD).
These known methods resolve an image of an image sequence into relatively small blocks of 1.times.1 (KDD) or, respectively, 4.times.4 picture elements (Mitsubishi) that are processed independently of one another. Although the data reduction of a vector quantizing (VQ) can be increased by increasing the block size, disadvantages result, such as an exponential increase the complexity of the required calculations, as well as a poorer matching to the image data.